FAMILIAR LETTERS ON CHEMISTRY. 23 



vol. xi., p. 411), a fat pig, overwhelmed in a slip of earth, lived one hundred and 

 sixty days without food, and was found to have diminished in weight, in that time, 

 more than one hundred and twenty pounds. The whole history of hybernating 

 animals, and the well established facts of the periodical accumulation, in various 

 animals, of fat, which, at other periods, entirely disappears, prove that the oxygen, 

 in the respiratory process, consumes, without exception, all such substances as are 

 capable of entering into combination with it. It combines with whatever is 

 presented to it ; and the deficiency of hydrogen is the only reason why carbonic 

 acid is the chief product ; for, at the temperature of the body, the affinity of 

 hydrogen for oxygen far surpasses that of carbon for the same element. 



We know, in fact, that the graminivora expire a volume of carbonic acid equal 

 to that of the oxygen inspired, while the carnivora, the only class of animals whose 

 food contains fat, inspire more oxygen than is equal in volume to the carbonic acid 

 expired. Exact experiments have shown, that in many cases only half the volume 

 of oxygen is expired in the form of carbonic acid. These observations cannot be 

 gainsaid, and are far more convincing than those arbitrary and artificially produced 

 phenomena, sometimes called experiments ; experiments which, made as too often 

 they are, without regard to the necessary and natural conditions, possess no value, 

 and may be entirely dispensed with ; especially when, as in the present case, nature 

 affords the opportunity for observation, and when we make a rational use of that 

 opportunity. 



In the progress of starvation, however, it is not only the fat which disappears, 

 but also, by degrees, all such of the solids as are capable of being dissolved. In 

 the wasted bodies of those who have suffered starvation, the muscles are shrunk 

 and unnaturally soft, and have lost their contractility ; all those parts of the body 

 which were capable of entering into the state of motion have served to protect the 

 remainder of the frame from the destructive influence of the atmosphere. Toward 

 the end, the particles of the brain begin to undergo the process of oxidation, and 

 delirium, mania, and death close the scene ; that is to say, all resistance to the 

 oxidizing power of the atmospheric oxygen ceases, and the chemical process of 

 eremacausis, or decay, commences, in which every part of the body, the bones 

 excepted, enters into combination with oxygen. 



The time which is required to cause death by starvation depends on the amount 

 of fat in the body, on the degree of exercise, as in labor or exertion of any kind, 

 on the temperature of the air, and finally, on the presence or absence of water. 

 Through the skin and lungs there escapes a certain quantity of water, and as the 

 presence of water is essential to the continuance of the vital motions, its dissipation 

 hastens death. Cases have occurred, in which a full supply of water being acces- 

 sible to the sufferer, death has not occurred till after the lapse of twenty days. In 

 one case, life was sustained in this way for the period of sixty days. 



In all chronic diseases death is produced by the same cause, namely, the chemical 

 action of the atmosphere. When those substances are wanting, whose function in 

 the organism is to support the process of respiration ; when the diseased organs are 

 incapable of performing their proper function of producing these substances ; when 

 they have lost the power of transforming the food into that shape in which it may, 

 by entering into combination with the oxygen of the air, protect the system from 

 its influence, then, the substance of the organs themselves, the fat of the body, the 

 substance of the muscles, the nerves, and the brain, are unavoidably consumed. 

 The true cause of death in these cases is the respiratory process, that is, the action 

 of the atmosphere. 



A deficiency of food, and a want of power to convert the food into a part of the 

 organism, are both, equally, a want of resistance ; and this is the negative cause of 

 the cessation of the vital process. The flame is extinguished, because the oil is 

 consumed ; and it is the oxygen of the air which has consumed it. 



In many diseases substances are produced which are incapable of assimilation. 

 By the mere deprivation of food, these substances are removed from the body with- 

 out leaving a trace behind ; their elements have entered into combination with the 

 oxygen of the air. 



From the first moment that the function of the lungs or of the skin is interrupted 

 or disturbed, compounds, rich in carbon, appear in the urine, which acquires a 

 brown color. Over the whole surface of the body oxygen is absorbed, and combines 

 with all the substances which offer no resistance to it. In those parts of the body 

 where the access of oxygen is impeded ; for example, in the arm-pits, or in the soles 

 of the feet, peculiar compounds are given out, recognisable by their appearance, or 

 by their odor. These compounds contain much carbon. 



Respiration is the falling weight the bent spring, which keeps the clock in 

 motion: the inspirations and expirations are the strokes of the pendulum which 



